This was done to reduce the need to switch from one app to another, according to Bill Doll of the Office’s team. Bill has also pointed out that the new singular Office mobile app also requires less storage space than individual apps.
While the new unified Office mobile app still generally have the same look and feel as per existing app which was done to provide a sense of familiarity to current users, it still comes with several new features. One of them is the ability to capture a picture of document or table and turn it immediately into editable Word document or Excel table respectively.
Users are also able to create a PowerPoint presentation by directly choosing photos from inside their phones. There is also the new Actions pane which allows quick access to a selected number of tasks that the Office team deemed are quite common for users on mobile devices such as PDF creation, file transfer between different devices, and scan QR codes to open files or links. While the new Office mobile app is currently available only for phones, Microsoft is already working to deliver the same experience on tablets. The public preview for the new app is now readily available for both Android and iOS although the quota for iOS has already maxed out at the moment as Apple TestFlight program has a maximum cap of 10,000 users. (Source: Office Apps Blog)
